241 research outputs found

    Efficient Resource Management Mechanism for 802.16 Wireless Networks Based on Weighted Fair Queuing

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    Wireless Networking continues on its path of being one of the most commonly used means of communication. The evolution of this technology has taken place through the design of various protocols. Some common wireless protocols are the WLAN, 802.16 or WiMAX, and the emerging 802.20, which specializes in high speed vehicular networks, taking the concept from 802.16 to higher levels of performance. As with any large network, congestion becomes an important issue. Congestion gains importance as more hosts join a wireless network. In most cases, congestion is caused by the lack of an efficient mechanism to deal with exponential increases in host devices. This can effectively lead to very huge bottlenecks in the network causing slow sluggish performance, which may eventually reduce the speed of the network. With continuous advancement being the trend in this technology, the proposal of an efficient scheme for wireless resource allocation is an important solution to the problem of congestion. The primary area of focus will be the emerging standard for wireless networks, the 802.16 or “WiMAX”. This project, attempts to propose a mechanism for an effective resource management mechanism between subscriber stations and the corresponding base station

    A Fair and Efficient Packet Scheduling Scheme for IEEE 802.16 Broadband Wireless Access Systems

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    This paper proposes a fair and efficient QoS scheduling scheme for IEEE 802.16 BWA systems that satisfies both throughput and delay guarantee to various real and non-real time applications. The proposed QoS scheduling scheme is compared with an existing QoS scheduling scheme proposed in literature in recent past. Simulation results show that the proposed scheduling scheme can provide a tight QoS guarantee in terms of delay, delay violation rate and throughput for all types of traffic as defined in the WiMAX standard, thereby maintaining the fairness and helps to eliminate starvation of lower priority class services. Bandwidth utilization of the system and fairness index of the resources are also encountered to validate the QoS provided by our proposed scheduling scheme

    MODULATION AWARE CONNECTION ADMISSION CONTROL AND UPLINK SCHEDULING ALGORITHM FOR WIMAX NETWORKS

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    Mobile WiMAX standard defines air interface for mobile broadband wireless access (BWA) systems and aimed to provide high data rate with seamless mobility while maintaining the quality of service (QoS). However, QoS of real-time applications depends on the link quality, which necessitate the channel-aware connection admission control (CAC) and scheduling schemes. In this paper Modulation aware CAC scheme and base station (BS) uplink scheduling algorithm are proposed to improve the system capacity and QoS performance respectively. The proposed CAC scheme aims to increase the admission of higher priority real time services by degrading the bandwidth of admitted lower priority connections on the basis of their channel status without deteriorating their QoS performance much. The performances of proposed algorithms are evaluated through simulation by considering the metrics like throughput, delay and number of connections admitted

    Connection admission control and packet scheduling for IEEE 802.16 networks

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    Includes bibliographical references.The IEEE 802.16 standard introduced as one of the Wireless Metropolitan Area Networks (WMAN) for Broadband Wireless Access (BWA) which is known as Worldwide Interoperability for Microwave Access (WiMAX), provides a solution of broadband connectivity to areas where wired infrastructure is economically and technically infeasible. Apart from the advantage of having high speeds and low costs, IEEE 802.16 has the capability to simultaneously support various service types with required QoS characteristics. ... While IEEE 802.16 standard defines medium access control (MAC) and physical (PHY) layers specification, admission control and packet scheduling mechanisms which are important elements of QoS provisioning are left to vendors to design and implement for service differentiation and QoS support

    Performance Evaluation of Connection Admission Control for IEEE 802.16 Networks

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    Quality of Service (QoS) provisioning to the various kinds of network traffic is one of the major design criteria of IEEE 802.16 WiMAX standard. The MAC and physical layers of 802.16 standards are designed to support different types of real time application by providing QoS. Scheduling, Connection Admission Control (CAC) and traffic policing are the major issues to ensure QoS. In standard, scheduling and admission control are kept as open issues. Admission control is the ability of a network to control admission of new traffic based on the availability of resources. As per the specification the CAC considers minimum reserved rate of a connection as an admission criterion, in which the system can admit more connections, but packets of admitted connection may encounter large delays. In this paper average data rate (avg-rate CAC) and maximum sustained rate (max-rate CAC) of the connections are considered as admission criteria in CAC, along with minimum reserved rate (min-rate CAC). The performance of the WiMAX network is evaluated and compared for min-rate, avg-rate and max-rate CAC by considering the performance metrics such as number of connections admitted, throughput and delay using QualNet simulation tool
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